Method and apparatus for retrieving junk from well bores



H. D. PYKE Aug. 17, 1954 METHOD AND APPARATUS FOR RETRIEVING JUNK FROM WELL BOREIS Filed April 29, 1950 INVENTOR. HER ERT DOUGLHSPYKE.

ATTORNEYS Patented Aug. 17, 1954 METHOD AND APPARATUS FOR RETRIEVIN G JUNK FROM WELL BORES Herbert Douglas Pyke, Compton, Calif. Application April 29, 1950, Serial No. 159,041

4 Claims. 1

This invention relates to the well drilling art and is particularly directed to an improved method and apparatus for recovering junk such as broken bit cores, bearings, and other small metallic parts from the bottom of the well bore so that drilling may proceed in a normal fashion.

Conventional tools for retrieving metallic junk from wells employ metal baskets provided with fingers which are designed to project under the junk to be retrieved as the pipe string is lowered, and then to be retained in the metal basket when the pipe string is withdrawn from the hole. The baskets with metal fingers are used with indifferent success because of the difiiculty of accurately controlling the operation at the bottom of a bore hole.

My invention avoids the use of metal fingers, and instead utilizes a tool having an open bottom cavity filled with clay or the like. When the tool is lowered to the bottom of the hole the roller cones, hearings or other junk are imbedded in the clay and are withdrawn with the pipe string when it is removed from the well bore. I prefer to use clay-in the tool cavity because it is cheap, readily available, and because it is not washed out of the cavity or socket by the action of the drilling mud in the well bore. I recognize, however, that other substances than clay can be used providing they have the desirable characteristics of being relatively soft and plastic to permit a foreign object to be imbedded and held tightly therein.

In the drawings:

Figure 1 is an elevation view partly in section showing a preferred embodiment of my invention, the body of clay being omitted.

Figure 2 is a plan view of the lower end of the device looking in an upward direction.

Figure 3 is an enlarged transverse sectional view of the lower end of the device shown in Figure 1 and showing the body of clay in place.

Figure 4 is a sectional view taken substantially on the lines 4-4 of Figure 3 showing the tool on bottom with a cone from a roller bit imbedded within the clay body.

Referring to the drawings, the body is tubular in form and is provided at its upper end with a threaded socket I l for reception of a threaded pin provided on the lower end of a pipe string (not shown). The central portion [2 of the body I 0 is provided with a plurality of downwardly directed lateral ports l3. Drilling mud pumped down the interior of the pipe string passes into the interior of the body [0 and flows outward through the ports l3 into the well bore so that circulation of drilling mud may .be continued while the retriever tool is in use and thereby prevents settling of the cuttings to the bottom of the hole.

A horizontal wall or divider plate It is positioned on the body 50 below the location of the lateral ports it. A frusto-conical downward flaring wall it is secured to the divider plate It and the lower portion of this wall i5 is preferably of a diameter approaching that of the well bore i6. A series of teeth I! are preferably formed on the lower extremity of the wall Iii. The walls I l and is are joined to the remainder of the body It by any convenient means such as, for example, by welding 18. It may be desirable in some cases to connect the wall IE to the intermediate portion [2 of the body by means of threads so that the wall I5 may be removed and replaced when necessary. The walls l4 and t5 cooperate to define a cavity l9 open at the bottom, and this cavity is filled with a body 2i? of relatively soft plastic material of clay-like consistency. The axial length of the cavity may be proportioned to accommodate the articles of junk known to be in the hole, if such information is available. As pointed out above, I prefer to use clay because of its availability and low cost, but other materials of the desired consistency will perform satisfactorily.

When the tool If] is lowered into the well bore on the lower end of the pipe string, the cuttings in the well bore are prevented from settling by the jets of mud fluid issuing from the lateral ports l3. When the tool In approaches the bottom surface 2| of the well bore any metallic junk such as roller cones, bearings, broken parts of bits, etc. which are resting on the bottom 2! are engaged by the teeth I 'l or by the clay body 28. The drill string and tool [0 are preferably rotated very slowly so that the teeth I! can mov pieces of junk toward the center of the well bore 16. The drill string and tool I 0 are gradually lowered while being slowly turned so that the junk is caused to become imbedded within the clay body. The actual imbedding operation may be carried out with the drill string and tool rotating or with them stationary. A portion of the weight of the drill string is applied to the tool l0, thereby forcing the junk into the clay body 20. As shown in Figure 4 the volume of the junk article 22 which is imbedded within the clay body requires that an equivalent volume of clay material be extruded from the cavity l9. This clay material is extruded through the spaces between the teeth I! into the annulus 23 between the wall l5 and I 3 the well bore l6. After the tool has come to rest on the bottom 25 the drill string and tool may be rotated to glaze the lower surface 24 of the clay body and thus seal the junk article 22 within the clay body 20.

It is also contemplated that the retriever tool it may be attached to a weighted member carried on the lower end of a wire line (not shown). The body in and weighted member may then be lowered into the hole on a wire line and the weight of the assembly used to force the junk resting on the bottom into the clay body 23. The Weight and body 10 may then be withdrawn by retracting the wire line from the well hole.

It is desirable to roughen or score the inner surface 25 of the frusto-conical wall It in order to form a mechanical bond for the clay body 20.

It will be understood from the above description that the clay body 26 is not exposed to the jet action of mud fiuidissuing from the ports it, so that the clay body 20 is retained within the open bottom cavity l9 and is not washed out of it.

Having fully described my invention, it is to be understood that I do not wish to be limited to the details herein set forth, but my invention is of the full scope of the appended claims.

I claim: 7

1. In a device for retrieving junk from the bottom of a well bore, the combination of a body insertable into the well bore and having walls providing a cavity open at the bottom, the lower end of the body having a series of longitudinally projecting teeth, the cavity being filled with relatively soit'plastic material of clay-like consistency so that junk resting on bottom may be embedded in said material by forcing the body downward and extruding a portion of said material through the spaces between said teeth.

Z. In a device for retrieving junk from the bottom or a well bore, the combination of a body insertable into the well bore and having a downward flaring frusto-conical wall, a series of longitudinally extending teeth on the lower extremity of the wall, means on the body cooperating with said Wall to define a cavity open at the bottom, the cavity being filled with relatively soft plastic material of clay-like consistency so that junk resting on bottom may be embedded in said material by forcing the body downward.

3. In a device for retrieving junk from the bottom of a well bore, the combination of a tubular body having a threaded portion for removably securing it to the lower end of a pipe string and insertable into the Well bore, a divider plate within the body, a downward flaring wall on the body cooperating with the divider plate to provide cavity open at the bottom, the tubular body having ports extending laterally therethrough communicating with the interior of the body above the divider plate so that mud fluid pumped through the pipe string may pass through the ports into the well bore, the said cavity being adapted to receive a body of clay or the like and having its inner surfaces prepared to form a mechanical bond with the clay body. 7

4. The method of retrieving junk from the bottom of a well bore comprising the steps of lowering a tool into the well bore on the lower end of a pipe string, the tool having an open bottom cavity filled with clay or the like, resting a portion of the weight of the pipe string on the tool to embed junk into the clay, rotating the pipe string and tool to glaze the clay and seal the junk therein, and retracting the pipe string and tool from the well bore.

References casein the file of this patent UNITED STATES PATENTS Number Name Date 7 398,396 Holden Feb. 26, 1889 598,725, Currie Feb. 8, 1898 1,410,904 Fitzpatrick Mar. 28, 1922 2,12%,772 Flory July 26, 1938 2,148,019 Graham Feb. 21, 1939 2,159,249 Brantly May 23', 1939 2,3 l5fl27 Burch Apr. 4, 1944 2,561,692 Fitch July 24, 1951 

